| 1. |
- Schael, S., et al.
(författare)
-
Electroweak measurements in electron positron collisions at W-boson-pair energies at LEP
- 2013
-
Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 532:4, s. 119-244
-
Forskningsöversikt (refereegranskat)abstract
- Electroweak measurements performed with data taken at the electron positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3 fb(-1) collected by the four LEP experiments ALEPH, DELPHI, 13 and OPAL, at centre-of-mass energies ranging from 130 GeV to 209 GeV. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose Einstein correlations between the two W decay systems arising in WW production, are searched for and upper limits on the strength of possible effects are obtained. The data are used to determine fundamental properties of the W boson and the electroweak theory. Among others, the mass and width of the W boson, m(w) and Gamma(w), the branching fraction of W decays to hadrons, B(W -> had), and the trilinear gauge-boson self-couplings g(1)(Z), K-gamma and lambda(gamma), are determined to be: m(w) = 80.376 +/- 0.033 GeV Gamma(w) = 2.195 +/- 0.083 GeV B(W -> had) = 67.41 +/- 0.27% g(1)(Z) = 0.984(-0.020)(+0.018) K-gamma - 0.982 +/- 0.042 lambda(gamma) = 0.022 +/- 0.019. (C) 2013 Elsevier B.V. All rights reserved.
|
|
| 2. |
- Schael, S, et al.
(författare)
-
Precision electroweak measurements on the Z resonance
- 2006
-
Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
-
Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 3. |
- Meijers, Judith M M, et al.
(författare)
-
Assessing the relationships between contextual factors and research utilization in nursing : systematic literature review
- 2006
-
Ingår i: Journal of Advanced Nursing. - : Wiley. - 0309-2402 .- 1365-2648. ; 55:5, s. 622-35
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper reports a systematic literature review examining relationships between contextual factors and research utilization in nursing, examining the strength of these relationships, and mapping the contextual factors to the Promoting Action on Research Implementation in Health Services model of research implementation.BACKGROUND: Healthcare organizations have long struggled with how to improve clinical care outcomes. Understanding which contextual factors enhance nursing research utilization may support organizations in creating environments that facilitate the uptake of evidence in nursing practice to improve these outcomes.METHODS: A search of five electronic bibliographic databases and a manual search of specific journals were conducted for studies that were published in English and examined contextual factors as independent variables and research utilization as the dependent variable from the perspective of nurses working in clinical practice. The studies were assessed for quality of design, sample, measurement and statistical analysis.RESULTS: Ten papers met the search criteria. Six contextual factors were identified as having a statistically significant relationship with research utilization, namely the role of the nurse, multi-faceted access to resources, organizational climate, multi-faceted support, time for research activities and provision of education. The contextual factors could successfully be mapped to the dimensions of context in the Promoting Action on Research Implementation in Health Services framework (context, culture, leadership), with the exception of evaluation.CONCLUSION: The strength of the relationship between the six contextual factors and research utilization by nurses is still largely unknown as (a) few studies were found of sufficient quality because of methodological limitations and (b) the results in reviewed studies were mixed. More robust methods in future work would yield a better understanding of the full impact of contextual factors on nurses' use of research.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Seers, K., et al.
(författare)
-
Facilitating Implementation of Research Evidence (FIRE): An international cluster randomised controlled trial to evaluate two models of facilitation informed by the Promoting Action on Research Implementation in Health Services (PARIHS) framework
- 2018
-
Ingår i: Implementation Science. - : Springer Science and Business Media LLC. - 1748-5908. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Health care practice needs to be underpinned by high quality research evidence, so that the best possible care can be delivered. However, evidence from research is not always utilised in practice. This study used the Promoting Action on Research Implementation in Health Services (PARIHS) framework as its theoretical underpinning to test whether two different approaches to facilitating implementation could affect the use of research evidence in practice. Methods: A pragmatic clustered randomised controlled trial with embedded process and economic evaluation was used. The study took place in four European countries across 24 long-term nursing care sites, for people aged 60years or more with documented urinary incontinence. In each country, sites were randomly allocated to standard dissemination, or one of two different types of facilitation. The primary outcome was the documented percentage compliance with the continence recommendations, assessed at baseline, then at 6, 12, 18, and 24months after the intervention. Data were analysed using STATA15, multi-level mixed-effects linear regression models were fitted to scores for compliance with the continence recommendations, adjusting for clustering. Results: Quantitative data were obtained from reviews of 2313 records. There were no significant differences in the primary outcome (documented compliance with continence recommendations) between study arms and all study arms improved over time. Conclusions: This was the first cross European randomised controlled trial with embedded process evaluation that sought to test different methods of facilitation. There were no statistically significant differences in compliance with continence recommendations between the groups. It was not possible to identify whether different types and "doses" of facilitation were influential within very diverse contextual conditions. The process evaluation (Rycroft-Malone et al., Implementation Science. doi: 10.1186/s13012-018-0811-0) revealed the models of facilitation used were limited in their ability to overcome the influence of contextual factors. © 2018 The Author(s).
|
|
